Method of forming a disposable diaper pad



Oct. 22, 1968 P. o. PHERSON ET AL 3,407,103

METHOD OF FORMING A DISPOSABLE DIAPER PAD 2 Sheets-Sheet 1 Original F'iled.Nov. 1, 1962 @Skbuq Q Pans? 0.?HERS0N nzuzls scnsoN cscn. RWATK NS Halt/nu F- UKG :mnss n. MURPHY mm a MEY Oct. 22, 1968 PHERSON ET AL 3,407,103

METHOD OF FORMING A DISPOSABLE DIAPER PAD Original Filed Nov. 1, 1962 2 Sheets-Sheet 2 HENZIE BS N CECIL H .WMKINS nnemN F'- DUKE U'Imas A MdrtPHY ATT RNEY United States Patent O METHOD OF FORMING A DISPOSABLE- DIAPER PAD Perry 0. Pherson, West Sulfield, Conn., Menzie Gibson,

Cecil H. Watkins, andMarian F. Duke, Toronto, Ontario, Canada, and James A. Murphy, New York, N.Y., assignors to Canadian International Paper Company, Montreal, Quebec, Canada, a corporation of Canada Original application Nov. 1, 1962, Ser. No. 234,641, now Patent No. 3,211,147, dated Oct. 12, 1965. Divided and this application July 26, 1965, Ser. No. 474,642

. 9 Claims.-(Cl..156202) ABSTRACT OF THE DISCLOSURE The continuous forming of disposable diapers in which strips are laid on an endless moving sheet in spaced relation to each other, an endless pad is laid on the sheet and strips, the side edges of the sheet are folded around the pad, and the enclosed pad is severed generally centrally of the strips.

Also, the forming of disposable diapers in which an endless pad is laid on an endless moving sheet, the side edges of the sheet are folded around the pad, and the pad is severed, the pad being laid with a central portion extending longitudinally of the sheet which is of greater thickness than flanking side portions.

This application is a division of U.S. application Ser. No. 234,641 filed Nov. 1, '1962, nOW U.S. Patent 3,211,147 which is, in turn, related to co-pending U.S. Ser. No. 86,734, filed Feb. 2, 1961, now abandoned.

This invention relates to a diaper pad of the disposable type. More particularly, it relates to a method for forming an easily manufactured, highly absorbent diaper for use with or without a diaper holder or panties which can be disposed of in househould toilets and septic tanks.

There are three primary objects of the diaper formed by the method of the present invention. The first is to provide infants with sanitary, efficient, and comfortable diaper protection; the second is to provide mothers and nurses with a diaper product which they can handle cleanly and dispose of readily when it is soiled; and, the third is to 'provide a diaper'product which is not only at least competitive as to utility and price with 'the'standard, reusable cotton diaper, but also can be fully disposed of in the most appropriate place, i.e., the household toilet or septic tank. By a broad aspect of the present invention, there is provided a method of forming a disposable diaper comprising the steps of continuously moving a sheet of tissue having a predetermined width along a given path in a direction parallel to its length, disposing strips of tissue transversely on the sheet with the centers of adjacent strips spaced a predetermined distance from each other, continuously placing an endless pad of loose fibers of cellulosic material on the sheet and strips with the pad extending longitudinally of the sheet, the pad having a width less than the predetermined width of the sheet,

folding portions of the sheet adjoining the pad around the pad to provide an envelope therefor, and severing the enclosed pad generally centrally of the strips so as to provide individual diapers each having a portion of one of a pair of successive strips at each of its ends. The diaper formed by the process of the present invention may be broadly defined as being made up of a center portion having longitudinal and lateral edges, side portions having longitudinal and lateral edges, end portions having longitudinal and lateral edges, an exterior wrapper, and exterior wrapper closure means. The center portion consists of a plurality of alternate and parallel batts or semi-columns of loose material and channel defining means. Each side portion has one of its longitudinal edges adjacent to or contiguous with a longitudinal edge of 'the center portion and consists of a plurality of alternate and parallel laths of loose material and channel defining means. Each end portion has one of its longitudinal edges adjacent'to or contiguous with a lateral edge of the center portion and lateral edges of the side portions and consists of at least one ply or layer of sheet materialqThe'exterior wrapper is disposed, preferably overlappingly, about the center, side and end portions and the closure means are positioned outwardly of or along the other longitudinal edges of the end portions. In a preferred embodiment of the finished diaper, the side portions are partially folded upon themselves and inwardly toward the center portion (with the channel defining means therein serving as pleat edges and the laths serving as pleat folds) and areheld in such position both for convenience in packaging and to provide a semi-contoured pad with which to cover the infant. Further, the closure means are provided with, at least, tearing indicia to enable the handler of the diaper, when soiled, to separate the center and side portions preparatory to or during disposal.

A clearer understanding of the product produced by the process of the present invention can be gathered from a review of the preferred, in-line, continuous manner of making it (according to the present invention) and the attached drawings in which 1 FIGURE 1 is an isometric view of the diaper of th present invention with elements thereof cut away;

FIGURE 2 is a plan view of a preferred type of closure utilized in the manufacture of the diaper of FIGURE 1;

FIGURE 3 is a sectional view of the closure means of FIGURE 2, taken along line 33;

FIGURE 4 is a sectional view of the diaper of FIG- URE 1, taken along line 4-4;

FIGURE 5 is an isometric view of the diaper of FIG- URE 1 when completed and just in or out of its package; and

FIGURE 6 is an isometric view of the diaper of FIG URE 1 when ready to be put on an infant.

In a typical example (according to an embodiment of the present invention) of the manufacturing of the diaper, a flat paper web 10 having width of about 32 /2 inches is continuously travelled in the horizontal plane. Preferably, web 10 consists of two-ply, 9% pound basis weight, 2% wet strength, crepe tissue having a 25% stretch and about three times the strength in the length as in the width. Next, at intervals of about 16 inches along the length of web 10, paper reinforcing strips 11 are manually or mechanically laid laterally across web 10. One way of doing this is to move the reinforcing strips longitudinally above and in a direction perpendicular to the path of web 10 and to allow one edge of the strips to trail down on moving web 10, so as to be drawn with the aid of such movement down upon such web. These reinforcing strips are preferably six separate, but stacked, plies or three doubledover layers of 9% pound basis weight, 2% wet strength crepe tissue paper having a 40% stretch and they measure approximately 5 inches by 12 /2 inches.

As tissue web 10 is being reinforced, a light'flutf pad web 12 is .being continuously travelled in a generally horizontal plane. Fluff Web is preferably about 12 /2 inches in width and consists of sulfite or sulfate wood pulp 13 which has been disintegrated or made into a loose material by means of commercially available machinery for that purpose and reformed into a pad having at least one, non-wet strength backing sheet 14 of paper tissue. Simultaneously, a second, main fluff pad web is continuously travelled in a horizontal plane and laid down on and 3 centrally of fluff web 12. Fluff web 15 is about 3 /2 inches wide and can have a greater thickness or height than fluff web 12, but its composition is generally the same as that of fluff web 12 and its structure includes the same sort of loose material 16 and support sheet 17.

Once the two fluff webs 12 and 15 are brought together, they are joined together by the provision of parallel channels 18a and 18b in and over the length of fluff web 15, and that component of fluff 12 underlying fluff web 15, by standard, preferably rotary, embossing means. Such embossing divides combined webs 12 and 15 into the longitudinal batts or semi-columns 19 which will form the center portions of the eventual diapers, as well as lightly welds the two pads together. i

As soon as the two pad webs 12 and 15 are thus joined together, they are ready to be laid down on and centrally of tissue web having reinforcing strips 11 and the three webs are conjointly travelled to a standard folding shoe or the like which causes web 10 to envelop, preferably overlappingly, still flattened webs 12 and 15.

After the folding of web 10, the several combined longitudinally moving webs, i.e., 10, 12 and are laterally embossed, centrally of reinforcing strips 11. Such embossing forms the closures of the eventual diapers and it is important that its character be given especial attention, because, if improperly done, can be the source of great discomfort and possible injury to the ultimate wearer of the diapers. It has been found, for instance, that when this embossing is accomplished by male and female dies, rather than two matched male embossing dies 30 as suggested in FIGURE 3, the result is a hardened paper strap, rather than the soft, cushioned, highly desirable band 20 of the present invention. Such embossing can, of course, be accomplished by standard, commercially available, but preferably rotary, means and it can be accompanied by the formation of diamond cuts 21, slits, or the like which are made to lie across the centerline of strips 11 and to run generally longitudinally with the combined webs, so as to furnish tearing indicia or means, preferably in registry with a channel 18a, for use when disposing of the diaper.

Following the lateral embossing which provides bands 20, the combined several webs 10, 12, and 15 are longitudinally embossed to provide parallel channels 22a and 22b on the side portions of the eventual diapers and to divide such portions into longitudinal laths 23 in a manner permitting a folding of such laths upon themselves (as illustrated in FIGURES 5 and 6) somewhat later in the process of manufacture. Then, glue spots 24 or the like are aflixed to the cover provided by web 10, midway between bands 20 and over the inboard laths 23; the side portions of the combined assembly are longitudinally pleated along the foldlines provided by channels 22a and 22b, so as to become partially fastened in place by glue spots 24; a peg or spot embossing 25 is provided on the outboard laths 23 as they overlie the inboard laths, in registry with glue spots 24, to complete the fastening; and, to end the process, the diapers are formed, and their closures are perfected, by laterally severing bands 20 along. their centerlines, so that one set of reinforcing strips 11 provides the end portions of two adjacent diapers. Again, the nature and means of this severing is most important to the comfort and safety of the diaper wearer. For, it has been found that a sharp knife cut produces a hard edge on the band which is not permissible against, for instance, an infants skin, while an extension of the pressure sealing shown in co-pending Ser. No. 86,734, .Wherein paper fibers are to an extent welded together, yields an acceptable product. Such a severing can be achieved by over-embossing along a line or using a shear cut to furnish diaper ends 26 without an abrading or chafing edge. Use of a band saw is also advantageous.

The outstanding merits of the product prepared in ac cordance with the present invention are manifest. No toilet or septic tank clogging materials are employed; the

product can be entirely composed of paper, or, more broadly, wood pulp derivatives. Again, the channels in the diaper which initially promote a better distribution of the discharged body fluids of the wearer and, therefore, a better absorption of such fluids better contour the garment to the wearer and then aid in its disposal by furnishing tearing lines. The diaper closures too present no disposal problem, since they utilizeno adhesives or non-paper materials. In addition, the obviate the inclusion of possible irritating compositions and avoid discomforting structures, and they provide sections of the diaper strong enough to permit the use of safety pins therethrough to hold the diaperswithout, if necessary, the use of rubber panties or the like.

We claim:

1. A method of continuously forming disposable diapers comprising the steps of continuously moving a continuous sheet of tissue having a predetermined width along a given path in a direction parallel to its length, continuously placing a continuous pad of cellulosicmaterial of the moving sheet with the pad extending longitudinally of the sheet, the pad having a width less than the predetermined width of the sheet, continuously folding portions of the moving sheet adjoining the pad around the pad to provide an envelope therefor, at regular intervals embossing the enveloped pad transversely of its length at uniformly spaced locations so as to unite the pad and envelope, continuously folding side edge portions of the moving pad inwardly and then back upon themselves to form longitudinally extending folds constituting pleats at the sides of the pad, fastening at least theinnermost fold of each pleat to the unfolded portion to retain the pleat in place, and serving the moving enclosed pad generally centrally of the embossing so as to provide individual diapers.

2; A method in accordance with claim 1 in which said endless pad is formed of loose fibers of cellulosic material.

3. A method in accordance with claim 1 in which said pad includes loose fibers of cellulosic material formed to include a central portion extending longitudinally of the sheet, said central portion having a greater thickness than flanking side portions.

4. A method in accordance with claim 1 including the further step of disposing strips of tissue transversely on said moving sheet with the centers of said strips spaced at predetermined distances to generally coincide with the centers of said uniformly spaced locations whereby severing the enclosing pad severs the strips to leave a portion of each strip at the respective ends of the individual diapers.

5. A method in accordance with claim 4 in which said strips are moved along a path extending above the sheet in a direction perpendicular to the path of the sheet and are transferred directly to the sheet from said path.

6. A method in accordance with claim 1 which includes the step of embossing the pad befoi'e it is severed with a series-of generally parallel longitudinally extending lines of embossment.

" 7. A method of forming a disposable diaper comprising the steps of continuously moving a continuous sheet of tissue having a predetermined width, along a' given path in a direction parallel to its length, continuously placing on the sheet an endless pad of loose fibers of cellulosic material formed to include a central portion extending longitudinally of the sheet and having a greater thickness than flanking side portions, said pad having a width less than the predetermined width of the sheet, folding portions of the moving sheet adjoining the pad around the pad to provide an envelope therefor, at regular intervals embossing the enveloped pad transversely of its length at uniformly spaced locations so 'as' to unite the pad and envelope, and severing the enclosed pad generally centrally of the embossing to provide individual diapers.

8. A method of continuously forming disposable diapers comprising the steps of continuously moving an endless sheet of tissue having a predetermined width along a given path in a direction parallel to its length, disposing strips of tissue transversely on the moving sheet with the centers of adjacent strips spaced at predetermined distance from each other, continuously placing on the moving sheet and strips an endless pad of loose fibers of cellulosic material formed to include a central portion extending longitudinally of the sheet and having a greater thickness than flanking side portions, said pad having a width less than the predetermined width of the sheet, folding portions of the moving sheet adjoining the pad around the pad to provide an envelope therefor, at regular intervals embossing the enveloped pad transversely of its length at uniformly spaced locations so as to unite the pad and envelope, and severing the moving enclosed pad generally centrally of the strips and the embossing so as to provide individual diapers, each having a portion of a pair of successive strips at each of its ends.

9. A method of continuously forming disposable diapers comprising the steps of continuously moving a continuous sheet of tissue having a predetermined Width along a given path in a direction parallel to its length, continuously placing a continuous pad of cellulosic material on the moving sheet with the pad extending longitudinally of the sheet, placing creped tissue reinforcements on said moving sheet to provide transverse strength for said diaper, continuously folding portions of a moving sheet around the pad and the reinforcements to provide an envelope therefor, at regular intervals embossing the enclosed pad, the reinforcements and the envelope transversely of the length of the enclosed pad at uniformly spaced locations, so as to unite the pad, reinforcements and envelope, continuously folding side edge portions of the moving united assemblage of pad, reinforcements and envelope inwardly and then back upon itself to form longitudinally extending folds constituting pleats at the sides thereof, and severing the moving assemblage generally centrally of the embossing so as to provide individual diapers with the pad, reinforcements and the envelope united and sealed at each end thereof.

References Cited UNITED STATES PATENTS 2,890,700 6/1959 Lonberg-Holm 128--284 2,916,037 12/1959 Hansen 128284 2,964,441 12/ 1960 Goldstone 156-209 3,043,733 7/1962 Harmon et a1 156-209 a EARL M. BERGERT, Primary Examiner.

H. F. EPSTEIN, Assistant Examiner. 

